Large-Area and Visible-Light-Driven Heterojunctions of In2O3/Graphene Built for ppb-Level Formaldehyde Detection at Room Temperature

作者：Lanpeng Guo, Hongping Liang, Huiyun Hu, Shenbin Shi, Chenxu Wang, Sitao Lv, Haihong Yang, Hao Li, Nicolaas Frans de Rooij, Yi-Kuen Lee, Paddy J. French, Yao Wang, Guofu Zhou · 发表于：ACS Applied Materials & Interfaces · 年份：2023 · DOI：10.1021/acsami.3c00218 · 被引用次数：31 · 研究领域：Gas Sensing Nanomaterials and Sensors、Analytical Chemistry and Sensors、Advanced Chemical Sensor Technologies

Achieving convenient and accurate detection of indoor ppb-level formaldehyde is an urgent requirement to ensure a healthy working and living environment for people. Herein, ultrasmall In 2 O 3 nanorods and supramolecularly functionalized reduced graphene oxide are selected as hybrid components of visible-light-driven (VLD) heterojunctions to fabricate ppb-level formaldehyde (HCHO) gas sensors (named InAG sensors). Under 405 nm visible light illumination, the sensor exhibits an outstanding response toward ppb-level HCHO at room temperature, including the ultralow practical limit of detection (pLOD) of 5 ppb, high response ( R a / R g = 2.4, 500 ppb), relatively short response/recovery time (119 s/179 s, 500 ppb), high selectivity, and long-term stability. The ultrasensitive room temperature HCHO-sensing property is derived from visible-light-driven and large-area heterojunctions between ultrasmall In 2 O 3 nanorods and supramolecularly functionalized graphene nanosheets. The performance of the actual detection toward HCHO is evaluated in a 3 m 3 test chamber, confirming the practicability and reliability of the InAG sensor. This work provides an effective strategy for the development of low-power-consumption ppb-level gas sensors.